THE STUDY ON MEASURING TECHNIQUE OF PARTIAL DISCHARGE IN GAS INSULATED SWITCHGEAR USING ULTRA HIGH FREQUENCY METHOD WITH EXTERNAL SENSORS

GISisusedwidelyallovertheworld,because theareaoccupiedbyaGISsubstationistypicallyon ly10-25%ofthatoftheequivalentairinsulated installation.Inordertoattainmorehighdegreeof reliabilityforGIS,thefailurescausedduringmanu facture,assemblinganderectionwillbeavo…     

体外预应力混凝土结构体外索的系统防护

体外预应力索是体外预应力混凝土结构的主要受力构件,其耐久性决定着结构的耐久性。应当采取有效措施对体外预应力索进行保护。为防止预应力索发生腐蚀,可以采取预应力索镀锌、涂层、增加套管等方法。为了提高预应力索系统的耐久性,可以采取提高钢索的耐腐蚀性、使用新型体外索材料、改进锚具、保证体外索防腐体系的质量等多种措施。     

利用体外预应力技术加固桥梁的配索设计

体外预应力结构主要由体外索、转向块、锚固系统及防护系统等组成,其中体外索的配筋设计是关键。结合实践,介绍了体外预应力加固旧桥的原理及配筋计算方法。     

广东港东江公路大桥悬臂T构桥梁维修

广州港东江大桥主桥为双悬臂T构与挂梁相结合的结构形式在多年运营后出现的各种病害,文章分析了病害原因并进行了结构计算分析基础上在此基础上提出采用体外预应力,更换混凝土挂梁,更换桥面铺装等维修改造措施.计算结果表明采用钢结构更换混凝土挂梁对改造该桥型起到很好的效果.     

Method Research on Measuring the External Costs of Urban Traffic Congestion

A main reason for congestion pricing is the external cost of congestion. Qualitative and quantitative analyses of the external costs that the urban traffic congestion brings are the basis of congestion pricing. First, this paper analyzes the production mechanism of urban traffic congestion: travelers overlook the negative externality of urban traffic congestion and then join the congested queues. Then, the external costs of traffic congestion are divided into four parts: extra travel time costs, environmental pollution costs, traffic accident costs, and fuel consumption costs. Consequently, an intensive study on the quantitative measurements for those four external costs is made. Also, a sample case is introduced to prove the feasibility of this method. It supplies a base for the implement of urban road congestion pricing and other travel demand management strategies.     

城市对外交通枢纽集疏运体系规划研究

从城市对外交通枢纽对集疏运体系功能要求入手,分析了枢纽集疏运体系规划应考虑的因素及规划原则。基于对城市与区域协调发展、集疏运发展模式选择、集疏运通道布局以及规划效果评价等方面综合考虑,提出了城市对外交通枢纽集疏运体系规划思路。最后,结合南京禄口国际机场集疏运体系规划实践,进行了实际应用分析与效果评价。     

深圳兴海月亮湾立交门架式桥墩结构分析

门架式桥墩在城市立交桥中应用越来越广泛,文章针对深圳兴海月亮湾立交匝道桥中的门架式桥墩进行建模计算．得出其受力和变形情况。针对计算结果中可能出现的应力集中问题和帽梁的开裂问题,分别采用构造措施和预应力分批张拉以及调整施工工序的方法予以解决。     

中心镇对外交通规划方法研究

中心镇是乡村型社区向城市化转变的过渡阶段。文章结合中心镇过境交通比重高、内外交通不协调、交通设施不完善等对外交通特征,围绕中心镇对外交通体系规划方法进行研究,从总体上构建了中心镇对外交通规划方法体系,从对外交通规划内容、思路和流程、规划方法等方面形成规划的总体框架。     

体外预应力节段预制拼装混凝土梁疲劳试验研究

为研究体外预应力节段预制拼装混凝土梁的抗疲劳性能,设计制作了1∶3缩尺模型,进行设计荷载下的疲劳模型试验研究。综合对比国内外多种疲劳荷载计算方法,确定试验疲劳等效荷载;在此基础上,进行了体外预应力节段预制拼装混凝土梁的抗疲劳理论分析和200万次疲劳加载试验。理论分析结果表明,节段预制拼装梁包含的混凝土和体外预应力构件抗疲劳能力具有较大余量,不控制结构的耐久性;试验结果表明,模型在200万次疲劳加载后,各部位均未发现疲劳裂纹,模型的力学特性未随循环次数的增加而发生明显改变,验证了结构设计的合理性和安全性。     

Health externalities of ship air pollution at port – Piraeus port case study

This paper is employing the well-known methodology of impact pathway approach to assess the external costs in human health from ship air pollution at port areas. The passenger port of Piraeus, Greece is the scenery of the study. Piraeus port is in the vicinity of the greater Athens metropolitan area where almost half of the country’s population lives. Hence, this port is the central hub of the Greek coastal passenger ship system which connects the islands of the Aegean Sea with land and is characterized by heavy ship traffic. The case study presented in this paper assesses the annual external cost in human health from air emissions produced by all passenger ships and cruise ships calling the port of Piraeus. Health cost from ships at port has been estimated at both local (Athens metropolitan area) and regional level (entire territory of Greece). Results show that higher costs occur at the local level. The dominant pollutants creating this cost are particulate matter (PM_2.5, and PM₁₀). Overall, the results indicate that the health impact of Piraeus’s passenger port emissions is not negligible; however the cost of PM₁₀ is considerably lower than the corresponded cost deriving from the land based industries of the Athens regional area for which comparison has been available.